Il misterioso caso di KIC 8462852 - The mysterious case of KIC 8462852
Un vampiro cosmico mangiucchia il bagliore della stella?
La Forza Oscura nasconde la Luce?
Gli extraterresti sono scoperti stati a rubare energia senza pagare la bolletta?
A cosmic vampire nibbles the glow of the star?
The Dark Force hides the Light?
Extraterrestrials have been caught stealing energy without paying the bill?
Index
1) KIC 8462852
2) Planet Hunters X. KIC 8462852 – Where’s the flux?
3) La stella dalla luce misteriosa. Gli astronomi: "Fa pensare a tecnologia aliena"
4) Scientists can’t explain what huge object is blocking the light from this distant star
KIC 8462852
English
Planet Hunters X. KIC 8462852 – Where’s the flux?
La stella dalla luce misteriosa. Gli astronomi: "Fa pensare a tecnologia aliena"
Tiziano Toniutti www.repubblica.it/scienze
L'anomalia rilevata dopo mesi di osservazione:
"Potebbe essere il segno della presenza di una civiltà avanzata".
Una stranaluce arriva da KIC 8462852, una stella proprio
sopra la via Lattea, in mezzo alle costellazioni del Cigno e della Lira, a 1481
anni luce da noi. Così strana che dopo averla osservata a lungo con il
telescopio spaziale Kepler, gli astronomi rimangono perplessi. E il professor
Jason Wright della Penn State University, a breve pubblicherà un report in cui
verranno delineati i contorni del mistero. Per almeno provare a capire cosa c'è
lassù. Perché il telescopio registra una peculiare intermittenza dei fotoni,
come se davanti a quella stella passassero delle "megastrutture",
magari realizzate da una civiltà aliena per carpire l'energia della stella. Con
picchi irregolari di ostruzione della luce della stella che arrivano anche al
22%. Insomma, una situazione inedita e diversa dal tipico scenario di
regolarità di questi dati che porta alla scoperta di un esopianeta. Ma perché è
così atipica la situazione di KIC 8462852, al punto che gli astronomi arrivano
a parlare di un argomento tabù per la scienza, civiltà extraterrestri avanzate?
Perché le informazioni che arrivano dal telescopio escludono ogni possibile
spiegazione eccetto una, uno sciame di comete attirate nell'orbita di KIC
8462852 da un'altra stella, o un impatto avvenuto in tempi distanti. Ma per il
verificarsi di questa condizione, KIC 8462852 dovrebbe essere molto più giovane
di quello che è. Dice Wright all'Atlantic: "L'ipotesi aliena è sempre
l'ultima che andrebbe considerata. Ma quello che vediamo è proprio qualcosa che
ci aspetteremmo che una civiltà aliena costruirebbe". Una volta esclusi errori degli strumenti e
letture sbagliate, certo.
A questo pensa Tabetha Boyajian di Yale: "Tutto
regolare."
Megastrutture intorno a una stella, delle "sfere di
Dyson" come quelle degli episodi di Star Trek, quindi. Tecnologia per
assorbire energia finalizzata al mantenimento della vita. Del resto, uno dei
metodi di ricerca di civiltà aliene avanzate è proprio l'individuazione di
possibili tecnologie. Così nella vicenda si inserisce anche Andrew Siemion,
direttore del SETI (Search for Extra-Terrestrial Intelligence). E l'ipotesi
aliena inizia ad essere presa piuttosto sul serio dagli scienziati. Il prossimo
passo, previsto per gennaio, sarà puntare un'antenna radio verso la stella per
verificare se esistono frequenze associabili a questo scenario. Se insomma
possa essere vero che attorno a KIC 8462852 ci siano dei giganteschi pannelli
solari alieni, installati quasi 1500 anni fa. O per verificare se qualunque
cosa abbia visto Kepler, sia ancora lì dopo tutto questo tempo.
Scientists can’t explain what huge object is blocking the light from this distant star
http://www.sciencealert.com/
They say we actually need to consider the possibility of aliens
It’s not every day that we have permission to throw "Aliens?" out there in relation to a confounding astronomical discovery - in fact, I don’t think we ever have. But the discovery of a strange pattern of light surrounding a distant star called KIC 8462852 has seen even the most sensible astronomers throw their arms up with a, "Sure, why not?" arguing that the possibility of advanced alien technology can’t reasonably be ignored.
"Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilisation to build," Jason Wright, an astronomer from Penn State University in the US, told "The Atlantic".
First up, though, a little about the star in question: KIC 8462852. Located about 1,500 light-years away between the Cygnus and Lyre constellations of our Milky Way galaxy, KIC 8462852 is brighter, hotter, and more massive than the Sun.
It was first discovered by NASA’s "Kepler Space Telescope" in 2009, and scientists have been tracking the light it emits ever since, along with the light of another 150,000 or so newly discovered stars. They do this because it’s the best way to locate distant planets - slight, periodic dips in a star's brightness signal the fact that it might have one or more large objects orbiting it in a regular fashion.
These brightness dips are usually very slight, with the stars dimming by less than 1 percent every few days, weeks, or months, depending on the size of the planet’s orbit, says astronomer Phil Plait at Slate.
What makes KIC 8462852 such a strange star to study is that not only are there way more dips of brightness than expected, these dips are highly irregular. There’s no periodic orbiting going on here, just a bunch of strange, light-blocking shapes with no discernible pattern to them.
And these dimming effects are significant. Scientists are reporting that at one point, the amount of starlight dropped by 15 percent, and then at another, 22 percent. And this tells us a whole lot, says Plait:
"Straight away, we know we’re not dealing with a planet here. Even a Jupiter-sized planet only blocks roughly 1 percent of this kind of star’s light, and that’s about as big as a planet gets. It can’t be due to a star, either; we’d see it if it were. And the lack of a regular, repeating signal belies both of these as well. Whatever is blocking the star is big, though, up to half the width of the star itself!"
The most obvious explanation for hundreds of irregular dimming events is that KIC 8462852 has a mass of space junk - all kinds of rocks and dust of varying shapes and sizes - circling it in tight formation, says Ross Andersen at The Atlantic. The only problem is that this only occurs when a star is young, and the evidence points to KIC 8462852 being mature. "If it were young, it would be surrounded by dust that would give off extra infrared light," says Andersen. "There doesn’t seem to be an excess of infrared light around this star."
"We’d never seen anything like this star," one of the researchers, Tabetha Boyajian from Yale University in the US, told him. "It was really weird."
So what’s going on here? There are a number of reasonable possibilities to consider, and yep, aliens is actually one of them. First off, the scientists have already ruled out the possibility that the information they’re working with is faulty. "We thought it might be bad data or movement on the spacecraft, but everything checked out," says Boyajian.
The best explanation we have is that at one point, another star passed into KIC 8462852’s system and the disturbance of gravity caused a huge mess of comets to be pulled in towards it before being expelled again. And there just so happens to be another star close enough to KIC 8462852 to make this a possibility.
"But that would be an extraordinary coincidence, if that happened so recently, only a few millennia before humans developed the tech to loft a telescope into space. That’s a narrow band of time, cosmically speaking," says Andersen.
And then there’s the question of the 22 percent dimming. Could a mass of comets really block that much light? When astronomer Jason Wright from Penn State got a look at the data, he said we need to consider that perhaps we’ve caught an advanced alien civilisation in the process of building something massive near KIC 8462852.
Plait points to the so-called Dyson Sphere from several science fiction stories: a gigantic sphere made of solar panels that completely encircles a star. And he’s not opposed to the idea:
"I actually kinda like it. I’m not saying it’s right, mind you, just that it’s interesting. Wright isn’t some wild-eyed crackpot; he’s a professional astronomer with a solid background. As he told me when I talked to him over the phone, there’s 'a need to hypothesise, but we should also approach it skeptically' (paraphrasing a tweet by another astronomer, David Grinspoon), with which I wholeheartedly agree."
What does that mean? It means we're allowed to get a little bit excited! Not because aliens are a likely possibility, but because we're in the middle of an awesome mystery the likes of which we haven't seen before in the history of space exploration. Word is that SETI (Search for Extraterrestrial Intelligence) Institute scientists are considering devoting their time to it, and hopefully more research teams will get involved too. We seriously cannot wait to see what they come up with.
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